OTTAWA—Prime Minister Stephen Harper won’t be bringing the news his Mexican host wants to hear, nor hearing any himself from U.S. President Barack Obama, as North America’s beleaguered Three Amigos converge on Mexico this week.

Officials say Harper will not announce an end to Canada’s contentious travel visa on Mexico — an omission that will make the prime minister’s trip “an unmitigated disaster,” says one analyst who has been advising the Mexican government.

Harper, meanwhile, can expect the cold shoulder from Obama on a major Canada-U.S. irritant: the long-stalled American decision on whether to approve the Keystone XL pipeline, which would pump Alberta oilsands bitumen to the southern Gulf Coast.